code: def _build_function_def(self):
      with ops.Graph().as_default() as g:
          # Inputs
          x = array_ops.placeholder(dtypes.float32, name="x")
          y = array_ops.placeholder(dtypes.float32, name="y")
  
          # Outputs
          sum_squares = math_ops.add_n(
              [math_ops.pow(x, 2), math_ops.pow(y, 2)],
              name="sum_squares",
          )
          sum_cubes = math_ops.add_n(
              [math_ops.pow(x, 3), math_ops.pow(y, 3)], name="sum_cubes"
          )
      fdef = graph_to_function_def.graph_to_function_def(
          g,
          g.get_operations(),
          [x, y],  # Inputs
          [sum_squares, sum_cubes],
      )  # Outputs.
      fdef.signature.name = "_whats_in_a_name"
      return fdef
  
imports: from tensorflow.python.eager import def_function
  from tensorflow.python.framework import constant_op
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import function_def_to_graph
  from tensorflow.python.framework import graph_to_function_def
  from tensorflow.python.framework import op_def_library
  from tensorflow.python.framework import ops
  from tensorflow.python.framework import tensor_shape
  from tensorflow.python.framework import tensor_spec
  from tensorflow.python.framework import test_ops
  from tensorflow.python.framework import test_util
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import math_ops
  from tensorflow.python.ops import variables
  from tensorflow.python.platform import test
label_desc: Use image node_id 1 for calling the FunctionDefToGraphTest obj's underlying member method code with example usage: obj._build_function_def() and returns: fdef